Universal power unit

Application of chip КР142ЕН12А (B) and unified transformer TPP255-220-50 allows to make a simple and reliable source of a food for various household devices.

Target tension of a source can smoothly be regulated by font in limits from 2 to 12 Century. The maximum current of loading 1 And, thus the amplitude of a pulsation of target tension does not exceed 2 мВ.

the Fig. 5.3

the Electric circuit of the device is given by font on fig. 5.3. The block is accurate according to the standard circuit of a consecutive compensatory voltage stabilizer. In order that on a chip of DA1 not to disseminate too big thermal capacity, in the stabilizer discrete switching of conclusions of secondary windings of the transformer by the switch section S2.1 is provided. R4 resistors are at the same time switched also... R7 of dividers of feedback for installation of border of adjustment of target tension. On each of поддиапазонов it is possible to establish the necessary tension the variable R3 resistor. The switch provides installation of ranges of target tension 2... 5, 5... 7, 7... 9, 9... 12 Century

the Chip of DA1 has internal protection against an overload. The indicator of work of a source is HL1 light-emitting diode.

For convenience of use the circuit can add p with the strelochny measuring voltmeter.

In a power supply design the transformer can replace p with more powerful of the same series: TPP276-220-50, TPP292-220-50, TPP319-220-50 (numbering of conclusions of connection of windings thus does not change, but dimensions and device weight will increase).

the Chip is calculated by font on work with a heat-conducting path, and it is necessary for fixing on a radiator, thus the radiator should not have electric contact to the design case.

For convenience of control of border of ranges of target tension tuning R4 resistors... R7 is better for applying multiturnaround, for example the type SP5-2 or SP5-14. Condensers are applied: С1, K50-29 type SZ; С2. С4 — K73-17.
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